Land ahoy? Navigating the genomic landscape of speciation while avoiding shipwreck.

If there is one certainty about speciation, it is that those who research the process are able to disagree about almost anything. Arguments have raged over how to define species, over the importance of spatial separation and, more recently, over whether peaks of differentiation in genome scans might point to barrier loci. The debate calling attention to the shortcomings of searching for ‘genomic islands’ (Noor & Bennett, 2009; Cruickshank & Hahn, 2014) has been important to clarify where we are heading before scarce research funding is blown on tortuous journeys (sensu Baird, 2017). With our review (Ravinet et al., 2017), we aimed to clarify some of the issues surrounding interpretations of genome scan data and to suggest a practical way forward in dealing with the confounding factors that might obscure the genomic signal of reproductive isolation (RI). As the commentaries in this issue show, there is clearly still room for discussion and deeper understanding, as well as a penchant for inventive and maritime themed titles. In the interest of space, we will not respond to all the points the commentaries make; instead, our aim here is to highlight, and expand a little, on some of the common themes raised.